Dan - 1, snapped head stud - 0
I swing by and pick up a new 7/16" X 14 tap today at lunch, and when I got home I figured I would just spend 5 minutes to clean the hole out with the new tap I broke the other one with last night, and move on to the next victim. Only, something seemed odd when I ran the tap in. I stepped back and looked - CRAP, the tap is coming out of the hole at a slight angle! I removed the tap and looked down the hole - the walls were real shiny and that is not right on a 60+ year old block. Thinking what the heck, I started the tap back in carfully feeling my way until I felt it start to jar towards the front of the engine, I placed more force on the tap handle towards the back of the engine - the tap started to straighten out, then I heard a faint "pop". Removing the tap again and fearing the worse, I discovered it popped a section of remaining stud material out of the original block threads. Encouraged, I ran it back in keeping force on the tap to ensure it ran true. After TWO HOURS and working very slowly and carefully, it is all cleaned up and nothing but original cast threads. The hole is a little loose for my likes (a bolt has to go in about 1/2" before it stops wobbling slightly in the hole and tightens up). Oh well - I would rather have a slightly loose hole than a crooked one. Extra sealant for that one
The next victim I discovered was in a blind hole. Nothing worked to coax it out but once again the tried and true drill it out and pick the threads. I got a tad off on this one also when centering, but found not only my Dremel chain saw grinding stone, but also my specialty metal shaping bit (it looks very similar to the thin long chain saw stone, but is made of spiral cut metal). I cleaned the thick side until I could faintly see threads, picked the top few theads and ran the tap down with plenty of oil. This one cleaned right up with no problems to a nice tight hole - time - 1 hour.
So, I am down to 8 broken studs from 12 - gaining ground. Drinking a cold one in celebration tonight.
Dan
I swing by and pick up a new 7/16" X 14 tap today at lunch, and when I got home I figured I would just spend 5 minutes to clean the hole out with the new tap I broke the other one with last night, and move on to the next victim. Only, something seemed odd when I ran the tap in. I stepped back and looked - CRAP, the tap is coming out of the hole at a slight angle! I removed the tap and looked down the hole - the walls were real shiny and that is not right on a 60+ year old block. Thinking what the heck, I started the tap back in carfully feeling my way until I felt it start to jar towards the front of the engine, I placed more force on the tap handle towards the back of the engine - the tap started to straighten out, then I heard a faint "pop". Removing the tap again and fearing the worse, I discovered it popped a section of remaining stud material out of the original block threads. Encouraged, I ran it back in keeping force on the tap to ensure it ran true. After TWO HOURS and working very slowly and carefully, it is all cleaned up and nothing but original cast threads. The hole is a little loose for my likes (a bolt has to go in about 1/2" before it stops wobbling slightly in the hole and tightens up). Oh well - I would rather have a slightly loose hole than a crooked one. Extra sealant for that one
The next victim I discovered was in a blind hole. Nothing worked to coax it out but once again the tried and true drill it out and pick the threads. I got a tad off on this one also when centering, but found not only my Dremel chain saw grinding stone, but also my specialty metal shaping bit (it looks very similar to the thin long chain saw stone, but is made of spiral cut metal). I cleaned the thick side until I could faintly see threads, picked the top few theads and ran the tap down with plenty of oil. This one cleaned right up with no problems to a nice tight hole - time - 1 hour.
So, I am down to 8 broken studs from 12 - gaining ground. Drinking a cold one in celebration tonight.
Dan